Conventionally, internal combustion engines include a cylinder block, also commonly referred to as an engine block, containing banks of cylindrical bores for receiving the engine's reciprocating pistons. Atop the engine block there are secured one or more cylinder heads. In many conventional internal combustion engines, the cylinder head defines part of the combustion chamber, and further includes mechanical components such as one or more camshafts, spark plugs, and parts of the valve train such as the valve lifters. In other conventional internal combustion engines, the camshaft or camshafts are disposed in the engine block. In such engines, the cylinder head may include fewer or even no (e.g., a “flat head” type engine) mechanical components.
Valve lifters for internal combustion engines translate cam lobe action through a mechanical linkage to operate the intake and exhaust valves. Guide means are usually employed to properly maintain the orientation of the valve lifter as it reciprocates in response to rotary motion of the cam shaft. More specifically, orientation of valve lifters is usually accomplished by forming a flat orientation surface on the valve lifter which is oriented to the axis of the valve lifter roller and cooperates with a guide engaging the lifter orientation surface to prevent rotation of the valve lifter about its axis. Usually, two parallel flat surfaces are defined upon each lifter located upon opposite sides of the lifter axis. Exemplary of conventional valve lifters and valve lifter guides in these respects are the patents of Moretz, U.S. Pat. No. 5,088,455, and Moretz et al., U.S. Pat. No. 6,257,189, the disclosures of which are incorporated herein by reference in their entireties.
Presently, valve lifter guides are secured directly to the engine block by means of bolts, such as taught in U.S. Pat. No. 5,088,455, metal springs, retainers, or other separate fastening components. The employment of such separate components slows production time and adds to the expense of engine manufacture.
One solution to the foregoing problem is found in the disclosure of Evans et al., U.S. Pat. No. 6,745,737, which teaches an internal combustion engine with an engine block and a longitudinal extending anti-rotation guide that is affixed in a receiving groove of the engine block. The guide is constructed as an injection molded component with a one-piece, molded-on, elastically expanded or deformable clip that engages in a complementary receiving contour on the engine block.